For 66 years the Glass-Steagall act reduced the risks in the banking system. Eight years after the act was repealed, the banking system blew up threatening the international economy. US taxpayers were forced to come up with $750 billion dollars, a sum much larger than the Pentagon’s budget, in order to bail out the banks. This huge sum was insufficient to do the job. The Federal Reserve had to step in and expand its balance sheet by $4 trillion in order to protect the solvency of banks declared “too big to fail.”
The enormous increase in the supply of dollars known as Quantitative Easing inflated financial asset prices instead of the consumer price index. This rise in bond and stock prices is a major cause of the worsening income and wealth distribution in the United States. The economic polarization has undercut the image and reality of the US as a land of opportunity and has introduced political and economic instability into the life of the country.
These are huge costs and for the benefit only of the rich who were already rich.
So, what we can say about the repeal of Glass-Steagall is that it turned a somewhat egalitarian democracy with a large middle class into the One Percent vs. the 99 percent. The repeal resulted in the destruction of the image of the United States as an open prosperous society. The electorate is very much aware of the decline in their economic situation, and this awareness expressed itself in the last presidential election.